The present invention relates to a packing member for gas-liquid contactors used in gas-liquid contact operations of a chemical reaction apparatus such as a cooling tower and an absorption tower. More particularly, it relates to a lattice packing member which can be stacked in plural layers by alternately arranging the layers at right angles with respect to the layer immediately adjacent thereto.
Air contaminants such as sulfur dioxide contained in the exhaust gas from thermal power stations are generally removed by passing the gas through a gas-liquid contactor. In a chemical reaction apparatus such as the system for desulfurizing flue gas using lime and gypsum, various packing members are used to improve the gas-liquid contact efficiency. A structure consisting of plural strips that are crossed to form a lattice is known as one such packing member. For example, plural longitudinal strips A standing upright on their edges are arranged in parallel and are crossed at right angles with plural lateral strips B also standing upright on their edges, to thereby form an integral lattice structure.
There are two types of packing member with such lattice structure. One consists of a greater number of longitudinal strips A than lateral strips B, the latter being arranged at a larger interval. Thus, the openings in the lattice structure seen in a plan view are formed as a rectangle as in Japanese Patent Application Laid-Open No. Sho 50-116372. The other consists of an equal number of longitudinal and lateral strips arranged in a criss-cross manner so that the openings in the lattice structure are formed as a square, as disclosed in Japanese Utility Model publication No. Sho 56-51923. These latticed packing members are made of injection-molded plastics and are stacked and installed inside a flue gas desulfurizing system.
In a gas-liquid contactor loaded with such packing members, contaminants are removed from the flue gas as the gas and liquid are contacted. As such, the flow pressure of the gas and the gas-liquid contact efficiency play an important role. Preferably, a packing member should be capable of preventing flow pressure and loss, achieving uniform gas flow, and promoting well-balanced and uniform distribution of gas and liquid in order to effect uniform chemical reactions. Further, they need to have sufficient strength as plural members are stacked one upon the other to facilitate easy loading into the system, and be free of lateral displacement.
In the lattice structure mentioned above in which the lattice openings are formed as a rectangle by allowing a larger interval for the lateral strips B than the longitudinal strips A, flow pressure loss of gas can be reduced. However, because of the larger interval of lateral strips B, the amount of liquid which comes in contact with and flows down along the packing member is small, making the contact efficiency of liquid far from satisfactory. With the other latticed packing member having square openings, one packing member is stacked on another member with an interval secured therebetween by means of projections provided at each junction of the lattice structure. Such packing member makes it difficult to load the same inside a system as the projections get in the way as the member is slid inside, involving troublesome manipulation for loading.